There has been known a technique which detects a state of display lamps provided in a product by using a captured image. For example, JP-A-2005-242915 discloses a technique where a monitoring device, which is attached to a rack of a server computer (a target product), detects by a monitoring camera a lighting state of an alarm LED which is provided in the server computer and indicates an abnormality. The monitoring device transmits information representing warning details according to the detected lighting state to a management computer.
However, in the above-described technique, since the warning details are transmitted to the management computer, it is not possible to allow a user to recognize specific information relating to the display state of the display lamps by outputting the specific information on an imaging terminal.